[Nut-upsuser] shutdown.return from a custom client

Jim Klimov jimklimov+nut at gmail.com
Tue Jan 3 08:55:57 GMT 2023

On Tue, Jan 3, 2023 at 8:18 AM Gennadiy Poryev via Nut-upsuser <
nut-upsuser at alioth-lists.debian.net> wrote:

> May be, I don't know. My UPS doesn't autopower on after charging its
> batteries full.
> Anyway how do I test it? There has to be some specific way of shutting
> down to see if that works or not.
> ...
> The problem is getting UPS to turn on the load as soon as power mains
> returns. Servers will start automatically. If a way to do this with my
> model is discovered, I will modify my daemon to use it instead of just
> load.off.delay'ing.
>> So, where do I look/dig ? Or is this a dead end and I better buy other
>> UPS model with an actual support?

Well, if buying is an option - maybe that would be a reasonable variant at
the moment, although there are a few more ideas to try first.

According to https://www.apc.com/us/en/faqs/FA158943/ "all APC Back-UPS"
models should auto-restart when charged, "independent with PowerChute
software either installed or not". So if yours does not, it may be
defective or have some different wiring/firmware/other internals that make
it deviate from the FAQ.

Recent decade's worth of APCs are also unfortunately known for very
rudimentary data/control support over USB HID protocol, promoting MicroLink
or ModBus over USB cabling, but nobody has yet contributed NUT drivers for

So on one hand, if you can source APCs older than approx 2010 - they might
work better (ones we had were pre-USB, with serial connections for Back
Pro's, and also SNMP cards in rack models - so different drivers and
different data model inside the device controller). But you may have issues
with expired batteries (PbAc's last about 3 years), dried-up capacitors,

On another hand, there is the "apcupsd" project with allegedly better
support than NUT currently has for modern APC protocols, as much as their
last commits happened 6 years ago (I've recently posted an idea that maybe
NUT should absorb it somehow - both are GPL). The two projects grew from
similar roots, and NUT has long provided an "apcupsd-ups" driver as
effectively a relay from apcupsd daemon to NUT ecosystem. Distro packaging
was reported flawed, making the two packages "conflict" per metadata on
some OSes, but custom-compiling the original projects to install side by
side should still work.

This is another vector you might try - at least to see if that project does
support your UPS better, and prove or disprove whether the device itself
supports an auto-poweron setting... maybe would suffice to toggle it once
and come back to NUT :) Also if you have a machine that can run APC
PowerChute - it could also help with this part of diagnostics and/or setup

Hope this helps,
Jim Klimov
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://alioth-lists.debian.net/pipermail/nut-upsuser/attachments/20230103/8d6963d6/attachment.htm>

More information about the Nut-upsuser mailing list